In reply to Simon Caldwell:
I think the RA have the clout they do partly because they have many members who are retired, so having plenty of time to dedicate to 'working for walkers'. The fact that they also tend to be educated and middle class with all that comes with this (nimby tendencies, a certain fear of 'riff raff' and those who are 'not like them' and so on) provides the motivation. Can't blame them really, its all seems to be part of the 'us and them', 'with and without', 'look after your own interets' structure of British society.
Never been ski-ing in Norway, (sob).
The 'continuous ruts' argument is frequently used but there seems to be no real evidence that it is a significant mechanism of erosion. Ground water run off is a problem but this applied to paths that are not used by bikes as well. It can usually be managed but the underlying problem is that many paths follow the natural fall line of water in any case. One thing that is certain is that wheel tracks, being continuous, draw the eye: they have a higher 'Gestalt' value then a set of scattered foot prints. Often the fact that such tracks draw the eye and that they usually occur on loose wet sections suggests that the wheel tracks cause the problem, as with my 'bog' analogy this is rarely the case.
The research I have read on the impact of cycles on trails shows they have a significant environmental effect only in very specialised environments such as as salt marsh, sand dunes and reed beds. Then again, walkers would also have a similarly high impact on such environments. However, even where walking has a significant impact on a sensitive habitat few see this as justifying the exclusion of walkers. (Example of this include erosion of peat in the Peak District and the Lake District).
Even if bikes do cause erosion problems in some locations surely it would only be fair to look to drainage, path constructions and so on as being the management solutions of choice, not the banning of cycles? After all this is the policy that is applied in order to manage all the erosion caused by walkers.
Land managers certainly don't seem to worry about the impact path construction has on 'the wilderness experience' when it is walkers who are causing the erosion problem. Just look at the miles of what look like old wooden conveyor belting used on sections of the 3 peaks walk.
Ultimately, all human activity has some environmental impact. However, references to this impact is often no more then a way to justify discrimination against a specific user group. Climbing is just the same, look at the bare rocks and erosion leading up to the roiutes in places like the Llanberis pass. Historically the creation of routes has involved extensive gardening and yet it might take 10,000 years for a mossy campion to establish itself on a ledge. For a study of the ecological impact climbing has on a cliff environment see
http://www.sciencedaily.com/releases/2002/04/020402072635.htm
Luckily, most outdoor users are pretty neutral about climbing, in the UK that cannot be said about cycling, either on or off road. Interestingly in more generally cycling friendly European countries no one seems to think that it is necessary to exclude cyclists from off-road paths. This months CTC magazine has a report on riding along the cliff paths of Normandy - I bet bikes are banned from almost identical paths in Cornwall though...
Regards,
Howard.